10 Reasons Your Pee Stinks

When you look into the bowl after taking a leak, you should see some pale yellow pee—a sign that you’re well hydrated and your urine is, well, healthy.

But how should it smell? We’re guessing you don’t give that a second thought. Unless, that is, you notice something suspect wafting up from the bowl.

Here, the top reasons your pee might reek, and medical advice from doctors about whether or not you need to make an appointment.

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Reason Your Pee Stinks: You're Dehydrated

Notice that your urine smells like ammonia? Just as not taking in enough H20 can leave your pee extra yellow, it can also make it extra smelly, too. When your body breaks down the protein you eat, a colourless compound called urea is formed, which is excreted through your urine, says urologist Mehran Movassaghi, M.D., of Movassaghi Urology in Santa Monica, CA.

Water dilutes the urea, so if you’re not hydrating enough, your pee will be packed with it – giving it a heavier ammonia-like smell, he says. A simple fix? Drink more water. If you rehydrate, your pee will usually grow lighter (and less stinky).

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Getty ImagesEkaterina Smirnova

Reason Your Pee Stinks: You Ate Something Different

Asparagus is notorious for making urine smell, um, different – but not everyone who eats the vegetable notices it. According to a study in BMJ, the pee these people produce after an asparagus-heavy dinner – usually described as pee that smells like sulphur – may be just as stinky, but they may lack the genes to be able to smell it.

The culprit is a particular sulfur compound found only in asparagus. But the food isn’t the only one to cause a switch in urine odor, Dr. Movassaghi says. Garlic – which also contains sulphur – and fenugreek, Brussels sprouts, curry, and high protein diets can also cause your urine to smell like fish or something rancid.

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Reason Your Pee Stinks: You Drank Extra Coffee

Coffee beans contain a compound called caffeol, which is released during roasting – giving coffee that delicious, drink-me-now aroma. But it’s insoluble in water, which means it remains intact as it runs through your system and out when you take a leak.

So if you drink enough coffee – especially if you’ve been skimping on water and you’re a little dehydrated—the caffeol will be more concentrated, says urologist S. Adam Ramin, M.D. of Urology Cancer Specialists in Los Angeles, Calif. And that can make your urine smell like coffee.

The smell is worse if you’re dehydrated, since you’ll also be dealing with that concentrated urea, which can amplify the aroma.

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Reason Your Pee Stinks: You Have a Urinary Tract Infection (UTI)

When an infection occurs anywhere in your urinary tract (think: a bladder infection or UTI), bacteria can change the color and smell of your urine, says Dr. Movassaghi.Usually, you’ll notice that your urine smells like ammonia or fish.

In the case of UTIs, the urine is often cloudy or bloody as well. Since the infections are usually caused by bacteria, an antibiotic from your doctor can wipe them out—and the resulting odor, although you may have a different smell in the meantime from the medication.

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Reason Your Pee Stinks: You Started a New Supplement or Medication

Some vitamins, medications, and supplements have ingredients that can change pee smell, and sometimes the appearance as well. Anyone who’s taken a multivitamin— –especially one that contains vitamin B – and peed neon yellow after can attest to that.

Medications like antibiotics can also lead to urine odor, because those that contain penicillin are derived from mold. That can give your urine a yeasty or fungus-like funk, but it should dissipate once you run through your antibiotic course.

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Getty ImagesPatrick Strattner

Reason Your Pee Stinks: You're on a Diet

Trying out keto or a low-carb diet? When your body’s low on sugar and carbs, it starts to break down fats and fatty acids for fuel. The result? A buildup of ketones, a type of acid produced by your liver. When ketones make their way through your system, you may notice sweet-smelling urine or even fruity breath.

While uncommon, a fistula, a.k.a. an abnormal connection between your bladder and your bowel (which is as gross as it sounds), can form when tissues separating the two are damaged. Usually, this is due to inflammation from Crohn’s disease or an infection in your digestive tract.

The result? Urine that smells like sulfur or even looks like stool, plus frequent bladder infections. If this sounds familiar, get yourself to the doctor for an X-ray—you could need surgery.

Kidney stones are hard deposits that form when chemicals in your urine crystallize and start to stick together. An urge to pee more often and a pungent urine odor can be signs of a kidney stone trying to work its way through your body (and possibly giving you a bladder infection in the process).

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